The Effect of Multiple-Brooding on Age Ratios of Quail

Abstract

Multiple-brooding in quail was once thought to occur rarely, if at all, and interpretations of recruitment were based on the assumption of single-brooding. Recent research on northern bobwhites (Colinus virginianus) indicates double- and triple-brooding occur in widely separated geographic areas. We developed time-free and time-based models of multiple-brooding to explore the role of this behavior in recruitment as indexed by autumn age ratios. Using empirical data on northern bobwhites, we found second and third broods contribute little to age ratios under a typical probability of nest success (0.3). Production is similar whether a hen quits laying after the first successful attempt, given 3 attempts, or whether a hen uses all 3 attempts. The time-based models suggest hatching phenologies obtained by backdating from wing molt may be biased (peak hatch is earlier than predicted by backdating). Management goals for high quail production should be to maximize the proportion of hens that lay, the probability of nest success, and the number of days in the laying season.